Walking tractor



- Attorney w. E. URSGHEL WALKING TRACTQRl 3 Shets-Sheet 1 `Filed June26,- 1945 WALKING- f 'rRAcToR Filed June 26, 1945' Dec. 13, 1949 w.URSCHEL 2,491,064

WALKING TRACTQR' 3 Sheets-Sheet 3 Filed June 26. 194151 554g@- y '77 a@wfg Patented Dec. 13, 1949 WALKING TRACTOR .vvilliamfE.lll1fschiel,Valparaiso, f-Ind.; Jue B. Urschel administrator of sad""Willam E.

Urschel, deceased 2 Claims.

`My, invention'relates-to improvements in walking tractors andit moreespecially. consists; of the features pointed routin the'lfollowmgdescripl tion.

`accumulation-,of earth; that provides a duplication of'poperatingparts-onthe left handand .right hand side of the machine; that employsadifvferential power drivebetweenA the two duplicate cams, rightuandleft, on the machineyand that it has a ,separate control `for eachsidetsoY that thepowercan be applied to` either side alone, thusfacilitating Athe turning', vof the tractor .within a very shortradius;y andfthat encloses all the, power mechanism and connectedcamsina..cas1ng,.to

.protect it.

With vthese and other related endsin view I illustrate on theaccompanyingdrawingssuchinstances y of f adaptation VVasy will disclosethe broad cooper-atingieatures of the mechanismwithout limiting" myselfto :theaspecic details. shown thereon and described herein.

Fig. 1 is a side elevation ofthe machine. Fig.,2,isV atop plan View ofFig. 1. Parts are shown in section.

Fig. 3 is a-top plan View of the frame Aof the machineA in assembledrelationV only with the main ,parts v Fig. 4 is an enlargedsplan of thecam portion of theentire machinerpartly in. section.

,l Fig. 571s an enlarged View of the` double roller cam follower,inlsection.

Fig. 6 isan enlarged.. diagrammatic view lillustrating the cylclev ofvoperationlof the `camsand associated legs.

Fig. 7 is atop `plans-viewer amechan-icallyconnected -front and rearfoot of. the .tread `portion of the machine.

Fig. 8 is a side elevation of the control forthe differential drive.

Fig. 9 is a partial perspective*view.of.,the leg structure for differentforms of legs.

Fig. 9a is an elevation of amodication ofthe leg 2B shown on Fig. 9.

In practicing my invention I may uselwhatever modifications of the`structurefor alternatives of function that the exigencies of. varyingconditions may demand without departing from the broad spirit of theinvention.

In contrast to so called Steppers` and conven tional endless treadtractors this invention includes a pair of front and rear feet oneach-side f2 of themachine whichv are duplicates ofseach other.--Infoperationat no time `is-,apairof-ffeet ,entirelyoffromthe ground.,As a foot is being` .raised anotherv neighboring foot -has .justen-:gagedlthe ground.

To control the movement of the legs and-connected feet two duplicate camgroups are provided each grouphaving ,an outside. duplicate cam and aninside duplicate cam.

Both of the outside camsI control the up and downl movement ofyalll the1legssand connected feet, and both ofthe insidecams controlt-he to andfro movement of` alle ,the-legsand their connected pfeetto cause, the;machine to travel v.over the ground.

,Theinside cams `are -madeheavier because they havethe heaviest workrtodoin moving the machine forward.,-While sonrie-,of` the -feetareinengagement with the ground andaare fstanding still.

The'up and down movement of some ofthe legs vandieet at the-beginningand at they end of each l IThis enablesA 1the operator to entirely stoplor variablymodiiythe movementof all the legsand feet ononelside ofthemachine from the legs and feeton the other sideso asto permit a sharpturningof themachineto the right or left.

A detailedidescription of the machine follows:

The frame l about midway` andtransverse of its length .has astationaryshaft 5 I`on. which .the sleeve portion 5i integral withcamsVSll-B'l and the diierential 39 are mounted. At v,each ,endof theframe .andtransverse thereof there isadisconnected rock shaft 9.Parallel4 rto the shaft. 9 thereisa duplicate rockt-shafted `Theseshafts have 4their-` abutting .ends 'l Lin` bearings 3 located centrallycrosswise l,of. the, frame. Atthe ends of these shafts thereare crankswhich actuate the up and down movement of the feet andtheir attachedlegs.

A central member 'l extends rearwardlyvfrom the engineY base to the rearHedge -ofthe iframe to-provide rigidity. Onit "bearings 3,l 54 and arelocated. The center member 1 is joined to the sides of the frame bytransverse members 6. Between bearings 54 and 58 the member 1 is dividedinto two parts, see Fig. 3.

The sides of the frame I have lateral bosses 2, 49 and 5U that formpivot points for separate rock arms (Fig. 2), which arms are joined bylinks that connect them to the respective cams 34-31.

An imaginary horizontal line 19 in Fig. 6 represents the extent ofactual ground traverse of a shoe I6 or I9. A second imaginary line 18represents the raised and reverse traverse of a shoe. The lines 18 and19 are joined by two reverse curves 80.

I plot the contour and extent of the required radii of the cam rollerpositions. The center of lines 18 and 19 is taken as a starting point onthe ground The entire length of these two lines and their connectedcurved ends 88 are divided arbitrarily into twelve distinct steps orpositions consecutively numbered up to twelvef parts as shown in Fig. 6.These positions are projected back through the connected levers, links,etc., to the cams where corresponding radii positions are located. Fromthese the changing contour of the cam grooves is determined and thevariations of the radii corresponding to the related points of thepositions of a foot is established.

In Fig. 6 the No. l position is at the center of the ground line 19.This position is also identified at 1 on the cam diagram, Fig. 6. Thisportion of the entire perimeter of the cam groove is the position of anactuating cam roller 63 or 64 corresponding to l on the ground line 19.The other roller positions on the cam grooves are similarly located fromthe other points on the lines 18-80.

The mechanism on one side of the tractor is a duplicate of thecooperating mechanism on the other side. For simplicity the descriptionis now conned to the single pair of front 22 and rear legs 23 on theleft side of the machine (Figs. 1 and 2). Immediately adjacent theseoutside legs 22, 23 there is a duplicate pair of inside legs 26, 21positioned next to the frame I.

There are two rigidly formed cams 34--31 forming one group to the leftof the center, lengthwise of the machine, facing from the front. Aduplicate cam group is positioned to the right of that center line andin axial alignment with the other cam group. On the inside of each camgroup there is the cam 34, 35 which serves to control the to and fromovement of both pairs of legs 22 and 26. On the outside of each camgroup there is the cam 36, 31 which only controls the up and downmovement of the feet.

At the upper end of each of the legs 22, 23, 26, and 21 (Fig. l) thereare outside cranks 24, 25, '28 and 29 which simulate the thigh portionof the human anatomy. These are attached to the outer ends of thetwo-part rock shafts 8 and 9. On the inside of the frame there areduplicate cranks 39 and 3|. The cranks 36 are on rock shafts 8 and 9,and the cranks 3| are on rock shafts 9 and 8.

On the outside of the frame, right and left, the bosses 2 serve for therock shafts 8 and 9. The inside bosses 49 are extended on the outside ofthe frame and serve as a bearing for the spindles 45 and the bosses 50serve for the spindles 41.

The free ends of the cranks 3| are connected by a link 32 at 14 and thefree ends of the cranks 3U are similarly connected at 14 by links 33.The links 32 are also connected to the free end 61 of the cam rollerrock arm 56 and the links 33 are similarly connected at 61 to the upperrock arm 56 (Fig. 2). The links 32 and 33 coact with the outside cam 36,31 to produce the up and down movement of the legs and feet. The links4|, 43, 52 and 53 are connected to the inside cam roller carrying rockarms 56 to produce a to and iro movement of the legs. They are actedupon by the inside cam 34, 35. There are eight of these cam rollercarrying rock arms duplicates of each other, four on the right and fouron the left and they all bear the same reference numeral, viz., 56.

The spindles 41 are connected to rock arms 44 and 48 and the rock arms44 are connected by links 43 to the inside legs 26 at 68. The rock arms42 on spindles 45 and the rock arms 46 are connected by links 52 to thelower cam roller rock arms under the control of the inside cam 34, 35.The inside rock arms 48 are supported on spindles 41 in the bosses 58.

The inside cam roller rock arm 56, the lower one, is pivoted on aspindle 51 positioned in the bearing 54. It is connected to the link 52and the upper link 53 is pivoted to the rock arm 48 at 14. All the pivotpoints of the ends of the links 32, 33, and 53 are designated by thenumeral 14 and all the pivot points on such links for the cam rollerrock arms are designated by the numeral 61.

A single roller and attached connections from a given cam will performone of the leg functions of the outside group of the front and rear legsand the cam roller diametrically opposite, on the same cam, at degrees,will perform the same function for the adjacent and inside group of afront and a rear leg.

In order to avoid the complications of conventional parallelogrammovements between the front and rear legs and their feet, I form thefront and rear feet as a part of a rigid connecting link such as I8 and2| connected respectivef ly to the feet- I6, I1 and I9 and 28. Thesefeet are pivoted to the lower end of the legs at 15. These connectedfeet are shown as a detached member on Fig. '1. This constructioninsures that the feet will remain flat during their entire cycle ofmovement. If desired the shoes 11 of rubber may be vulcanized to therespective metal feet and the feet may be made removable from the legsso as to be replaced by different sizes to accommodate the machine toterrain that is more or less soft and soggy and if desired additionalfeet or shoes may be provided between the front and rear legs bystiiening the links I8 and 2| and placing attachable and detachable feetthereon.

In practically constructing the machine for actual heavy duty operationI may make the legs 22, 23, '26 and 21 of rectangular cross section orof round cross section 69 shown in Fig. 9a. When formed of round crosssection the structure would be tubular to save weight.

The legs 22, 25, 23 and 21 are pivoted at their upper end at 13 to theirrespective cranks 24, 25, 28 and 29. The stationary shaft 5 is supportedin bosses 4 on the inner face of the frame.

To protect the working parts of the machine an upper cover I I enclosesthe engine I8 and with an underneath cover I2 secured to the frame formsan oil tight compartment. The lower casing has a drain outlet 16. A seatI3, Fig. 1, is for the operator and a transmission lever I4 gives himcontrol over the engine movement and a pair of differential levers l5,see Figs. 2 and 8, control the progress of the tractor. These handlevers may have the usual rachet segment and interacting spring pressedteeth. They are pivoted to the engine support and a link 1l connectseach lever to one of the differential brake disks 38 (Fig. 3) by meansof a band 10 (Fig. 8).

The differential gear 39 is connected by a pinion 40 which in turn isconnected by two bevel gears to the engine shaft. If the operator wishesto turn the machine to the right he pulls the right hand lever I5. Thisaction, through the diierential will stop the articulated legs on theright hand side of the machine or if the lever l is not pulled to itsmaximum extent the right hand legs in their movement will be onlypartially stopped. By this control the machine can be readily andquickly turned to the right or left as desired. When a left turn isintended the left hand control lever l5 will be used in the same way(Fig. 2)

The cam roller rock arms 54 are pivoted on a spindle 51 positioned inthe bearing 58. A similar short spindle 51 forms a pivot for the otherroller bearing rock arm 56 (Figs. 1 and 2).

In order to avoid a reversal ofrotation of the cam rollers 63 and 64 Iform them of different diameters. These rollers are supported bythreaded pins 59 (Fig. 5) which have two diierent diameters 60 and 6I.On these diameters needle rollers 65 are held in place by roller cages66. In this construction, Figs. 4 and 5, on one set of pins 59`the largecam internal ring 34 and the smaller diameter rollers 63 roll on theexternal cam ring 35. This construction leaves a clearance 62 adjacentthe roller 63. It insures that the rollers 63 and 64 do not reversetheir rotation during the revolution of the cams. In contrast, on thecam 36, 31 the small roller 63 engages the internal cam 36 and thelarger roller 64 engages the external cam 31, Fig. 4.

What I claim is:

1. In a walking tractor, a supporting frame, a source of power on theframe, a plurality of interconnected pairs of front and rear legs oneach side of the frame, a separate compound cam unit for each pair oflegs, each cam unit having two bearing faces, a diierential drive fromthe source of power positioned between the cam units, one bearing faceof a cam serving to control the up and down movements of both pairs oflegs, and the other face of said cam serving to control the to and fromovements of both pairs of legs.

2. In a walking tractor, a supporting frame, separately connected to asource of power on the frame, a pair of separate front legs a pair ofseparate rear legs pivoted to the frame at each side thereof, a pair oflinks at each side respectively connecting a corresponding front andrear leg together, means for coordinating movements of the separatepairs of legs independently of each other to maintain a walking pace ofall the legs in related steps, said means composing a pair of separatecompound cams on each side of the tractor for controlling all themovements of the legs.

WILLIAM E. URSCI-IEL.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 916,702 Hartt Mar. 30, 19091,266,774 Delo May 21, 1918 1,309,053 Adams July 8, 1919 1,382,854Rasmussen June 28, 1921 1,500,723 Roy July 8, 1924 1,560,325 Roy Nov. 3,1925 1,691,233 Ehrlich Nov. 13, 1928 1,798,104 Palmer Mar. 24, 1931FOREIGN PATENTS Number Country Date 560,657 France July 16, 1923

